Passive solar straw bale firestation in Guffey, Colorado.
Sara and Fergies house in Manitou Springs, Colorado.Burbophobia
This is my plan design 1042 (sq. ft.). (Owen Geiger designed the structural system...three 2 x 4's forming a post with a notch for the gluelam), which we build for Habitat for Humanity in Pueblo, Colorado.
One of the S.B. houses going up at El Dorado Ranch, San Felipe, Baja California, Republic of Mexico.
I have a bunch of miscellaneous photos that I desire to put up on my site without any real organization or focus. The first one, on the right, is window detail of a load bearing structure. This is a self supporting straw bale wall with a 2" by something wood rough buck to support the window. Above the window opening is a angle iron (ladder) lintel that carries and spreads the weight of the roof.
Note the black plastic over the top of the wall to protect against rain during non working hours. Also note the cross bracing to the keep the rough buck in alignment.
Next is a photo of a load bearing residence in rural new Mexico showing the ladder top plate which will support the roof and spread the loads over the straw bale walls to the foundation. This particular house has a hip roof with the roof loads spread between the four walls.
If it were a gable roof, the loads would be placed on the long walls only. There are many different top plate designs out there ranging from the ladder shown to box beams to concrete poured in place. While few or no wood members are used to hold up the roof (posts), considerable wood is used to make the "top plate". This plate must be securely connected to the foundation to prevent the roof from blowing away. There are several methods for making this connection. Of course every attempt must be made to provide a level plate.
The next photo shows the first three bales placed on a heavy concrete slab foundation. It appears a metal sheet has been placed directly over the concrete to prevent moisture migrating up into the bales, and possible to act as a termite shield, and maybe a stop for the stucco. Note that the bales are turned on edge, with the strings out. Sometimes the bales are placed flat with the strings not exposed. There are advantages and disadvantages to both.
In this case, the roof is supported by posts set inside the bales, thus exposed to the inside of the house. The posts can also be placed inside the bales by notching around them, or exposed to the outside. Again, there are advantages and disadvantages to all three systems.
The next photo is taken in a lab somewhere in New Mexico. It represents one off many controlled tests to determine the ability of stacked straw bales to support the heavy weight of a roof system.
Depending on the quality of the bales, and the weight of the roof, for example, the bales will compress somewhat under the weight, but easily support a typical roofing system. Once the bales are stuccoed and plastered, the weight carrying capacity is greatly increased based on the structural qualities of the wire reinforced concrete stucco. And plastered straw bale walls are far superior to frame walls in resisting fire. For tests to confirm these claims, please see resources under "BOOKS" above.
NOTE: I have many more misc. photos which I will add here as I find the time, please check back, Thanks, Robert. DAVES PLACE IN NORTHERN UTAH
This plan started with an "eye" shaped footprint, then evolved to an "eyelash" with a south extension and two symetrical covered entries, and a curved wall of south facing windows. Obviously, the structure is post and beam with the posts set outside the walls and therefore exposed. This is the first time the plan has been built, and of course we are finding some "weaknesses" in the design.
For one thing, the posts are rather close to the bale walls in places, making plastering difficult. Another, the free standing straw bale walls are not attached directly to the post/beam system thus requiring more internal stabilization. I haven't asked Dave about this, but the covered entries may not be wide enough (five feet) to be practical as porches. The heavy log cross braces required by the engineers for laterl loads (read wind), may have looked better on the corners (although they look good here).
Dave tells me he really likes this plan, but obviously he is an exceptional builder, able to deal with major challenges in a convincing, artistic and workmanlike way.
Dave is sending me photos as he builds plan 1190 Eyelash in Northern Utah. Here we see the exterior post and beam system which will support the roof trusses. The posts are larger than required structurally but were harvested from Daves land and will look great in front of the straw bale walls. Somebody has done some very nice work here.
You can see the treated plate used to raise the bales above the level of the foundation. Also note the rebar set into the concrete to pin the first course of bales. These are not required in all cases but are a good idea here because the walls are basically free standing, set inside of and not connected directly to the post/beam system.
Hopefully there is a slight slope from the plate to the perimiter so moisture will move to the outside.
Here we see the foam sheets set in place for the "shallow frost protected foundation" which is somewhat unusual but well tested. It elliminated the need for a deep footing in this cold Norther Utah climate. Is it worth the effort
Here are the forms in place for the shallow frost protected footings. I was not on the site so am trying to interpret what we are seeing. Looks like small footings inside the outer perimiter to support the sheer wall required by the structural engineer. Dave reports that the "frost protected shallow foundation" is a lot of work, maybe more than a more conventional footing. He has a large straw bale utility/garage structure on the property with hydrophonic concrete floor heat using foam insulation under the slab, and set at 65 degrees. This system has used about 35 gallons of propane this winter.